1. Field of the Invention
This invention concerns the use of a combination of low and high molecular weight polyalkylmethacrylates to reduce the pour point of a wax isomerate.
2. Description of Related Art
The addition of polyalkylmethacrylates to lubricating oils is known. For example, U.S. Pat. No. 2,628,225 discloses that polyalkylmethacrylates can be used as VI improvers and pour point depressants in lubricating oils. More recently, European Patent Application D 140 247 discloses that the pour point of a lubricating oil can be reduced by adding a mixture of acrylate or methacrylate polymers. Each polymer contains several acrylate or methacrylate esters. The molecular weight of both polymers ranges from 50,000 to 500,000.
However, neither reference suggests reducing the pour point of a wax isomerate using the particular combination of low and high molecular weight polyalkylmethacrylates as described below.